1. Field of the Invention
The invention relates to a multi-position adjustable height seat post, specifically a tube within another tube that allows for the adjustment of seat height to multiple positions while riding a bicycle.
2. Description of Related Art
Cyclists, specifically those involved in mountain hiking, find that it is beneficial to have a variety of seat height options while riding a bicycle. Seat height options are desired because they afford the rider greater control of the bicycle over widely varying terrain.
U.S. Pat. No. 8,079,772 patent had disclosed a multi-position bicycle seat post locking assembly. This invention provides for a multi-position adjustable height bicycle seat post locking assembly comprising an inner tube slidably supported within an outer tube. The outer tube has a smaller diameter so as to be received in the seat tube of a bicycle. The inner tube is adjustable, moving freely within the outer tube when not in a locked position. The direction of movement is based upon rider input. Either downward via rider weight or upward via spring force. The outer tube accommodates a locking assembly consisting of ball bearings, a lock ring, a compression lever, a spring, and an upper and lower retaining unit. The locking mechanism works by forcing ball bearings via the lock ring into corresponding spherical detent elements on the inner tube through holes in the outer tube. The inner tube can have multiple positions of height adjustability depending on the number of spherical detent elements provided in the inner tube. The lock, ring is cut with a steep angle at its top portion transitioning to a shallower angle below the steep angle. In the locked, position the lock ring is forced upwards onto its shallow angle via spring force which holds the ball bearings in the corresponding spherical detent elements within the inner tube. This shallow angle along with constant spring force on the lock ring allows the locking mechanism to self adjust to along the shallow angle of the lock ring as the seat post wears into its working position. Unlocking the mechanism consists of forcing the lock ring off its shallow angle position, past its steep angled position, and onto an upper zero angled position. This allows the ball hearings clearance to exit the spherical detent elements of the inner tube so that the inner tube moves freely within the outer tube.
Secondarily, the ball bearings are used to keep the inner post from twisting side to side as it travels longitudinally from position to position. This is done by forcing the ball bearings to track within channels of the inner tube. The channels run vertically from pocket to pocket along the inner tube. The inner tube is under constant force from a spring contained within the outer tube acting to extend the inner tube to its most extended position.
But this kind of seat post has some drawbacks below: First, after using certain period of time, the appearance of the inner tube will be wearing in virtue of the wear happened between the inner tube and the ball bearings when riders are adjusting the height of the seat post. This will result in quick ageing of the product appearance. Second, the progress of manufacture is difficult in virtue of the process of components.
The present invention has arisen to mitigate and/or obviate the disadvantages of the conventional.